Examining the Ziggo Ubee modem

26 August 2014

I bought a (older) second-hand Ziggo router on Marktplaats (dutch craigslist), because I didn’t want to experiment with my own router ;-). After opening the router, investigating the print, I saw 5 connectors, looking surprisingly much like a serial connector.

Connecting a multimeter to these connectors, I noticed that the voltage was changing during the boot process. This indicates a serial connector showing messages during startup.

COMMAND: read_memory
USAGE: read_memory [-p] [-c] [-s ElementSize{1..4}] [-n NumberOfBytes{1..16384}] [StartAddress]
DESCRIPTION:
Displays the contents of memory (in hex and ASCII) to the console.
StartAddress : the address to start displaying (can be memory, registers,
etc).
-s : sets the element size to be read (1, 2, or 4 bytes). Most useful for
registers; defaults to 1.
-n : sets the number of bytes to be read. Defaults to 16. Note that this
will always be padded out to a multiple of the element size.
-c : increments the start address by the number of bytes before reading.
This is most useful for continuing the previous read (with the same
parameters).
-p : prints the current options (which would be used if not otherwise
supplied).
If no parameters are specified, it will perform the last read again.
NOTE - the parameters are remembered from one read to the next; e.g. if you
set the element size to 4 bytes, then all subsequent reads will use this,
unless explicitly overridden.
WARNING - it may be possible to make the system hang or crash if you read
from an illegal address!
EXAMPLES:
read_memory -s 4 -n 64 0x80001234 -- Reads 64 bytes as 32-bit values.
read_memory -n 32 0x80001234 -- Reads 32 bytes starting with the
specified address.
read_memory -c -- Reads the next 32 bytes, continuing
from the previous read.
CM> read_memory -s 4 -n 64 0x82abe21c
82abe21c: 82ab99b8 00004000 82ab99b8 82abd7e8 | ......@.........
82abe22c: 80729be4 81399c10 82abe234 82abe234 | .r...9.....4...4
82abe23c: 00000017 00000000 82abe20c 00000000 | ................
82abe24c: 00000000 0722f6d7 00000000 00000000 | ....."..........